The price of performance: a cost and performance analysis of the implementation of cell-free fetal DNA testing for Down syndrome in Ontario, Canada

Impact of Structural Differences on the Modeled Cost-Effectiveness of Noninvasive Prenatal Testing

BACKGROUND

Noninvasive prenatal testing (NIPT) was developed to improve the accuracy of prenatal screening to detect chromosomal abnormalities. Published economic analyses have yielded different incremental cost-effective ratios (ICERs), leading to conclusions of NIPT being dominant, cost-effective, and cost-ineffective. These analyses have used different model structures, and the extent to which these structural variations have contributed to differences in ICERs is unclear.

AIM

To assess the impact of different model structures on the cost-effectiveness of NIPT for the detection of trisomy 21 (T21; Down syndrome).

METHODS

A systematic review identified economic models comparing NIPT to conventional screening. The key variations in identified model structures were the number of health states and modeling approach. New models with different structures were developed in TreeAge and populated with consistent parameters to enable a comparison of the impact of selected structural variations on results.

RESULTS

The review identified 34 economic models. Based on these findings, demonstration models were developed: 1) a decision tree with 3 health states, 2) a decision tree with 5 health states, 3) a microsimulation with 3 health states, and 4) a microsimulation with 5 health states. The base-case ICER from each model was 1) USD$34,474 (2023)/quality-adjusted life-year (QALY), 2) USD$14,990 (2023)/QALY, (3) USD$54,983 (2023)/QALY, and (4) NIPT was dominated.

CONCLUSION

Model-structuring choices can have a large impact on the ICER and conclusions regarding cost-effectiveness, which may inadvertently affect policy decisions to support or not support funding for NIPT. The use of reference models could improve international consistency in health policy decision making for prenatal screening.

HIGHLIGHTS

NIPT is a clinical area in which a variety of modeling approaches have been published, with wide variation in reported cost-effectiveness.This study shows that when broader contextual factors are held constant, varying the model structure yields results that range from NIPT being less effective and more expensive than conventional screening (i.e., NIPT was dominated) through to NIPT being more effective and more expensive than conventional screening with an ICER of USD$54,983 (2023)/QALY.Model-structuring choices may inadvertently affect policy decisions to support or not support funding of NIPT. Reference models could improve international consistency in health policy decision making for prenatal screening.

A comparative analysis of non-invasive prenatal testing in Ontario and Quebec: the role of governing style in health technology innovation & adoption

BACKGROUND

While processes of adoption and the impacts of various health technologies have been extensively studied by health services and policy researchers, the influence of policy makers' governing styles on these processes have been largely neglected. Through a comparative analysis of non-invasive prenatal testing (NIPT) in the Canadian provinces of Ontario and Quebec, this article examines how decisions about this technology were shaped by contrasting political ideologies, resulting in vastly different innovation and adoption strategies and outcomes.

METHODS

A comparative qualitative investigation comprising of a document analysis followed by semi-structured interviews with key informants. Interview participants were researchers, clinicians, and private sector medical laboratory employees based in Ontario and Quebec, Canada. Interviews were conducted both in person and virtually- owing partly to the COVID-19 pandemic - to garner perspectives regarding the adoption and innovation processes surrounding non-invasive prenatal testing in both provinces. All interviews were recorded and transcribed verbatim and data were analyzed using thematic analysis.

RESULTS

Through an analysis of 21 in-depth interview transcripts and key documents, the research team identified three central themes: 1) health officials in each province demonstrated a unique approach to using the existing scholarly literature on NIPT; 2) each provincial government demonstrated its own preference for service delivery, with Ontario preferring private and Quebec preferring public; and finally, 3) both Ontario and Quebec's strategies to NIPT adoption and innovation was contextualized within each province's unique financial positioning and concerns. These findings illustrate how both Quebec's nationalist focus and use of industrial policy and Ontario's 'New Public Management' style had implications for how this emerging healthcare technology was made available within each province's publicly-financed health system.

CONCLUSIONS

Our study reveals how these governments' differing approaches to using data and research, public versus private service delivery, and financial goals and concerns resulted in distinct testing technologies, access, and timelines for NIPT adoption. Our analysis demonstrates the need for health policy researchers, policy makers, and others to move beyond analyses solely considering clinical and health economic evidence to understand the impact of political ideologies and governing styles.

Utility of expanded carrier screening in pregnancies with ultrasound abnormalities

OBJECTIVE

Explore the utility of expanded carrier screening in evaluating heritable causes of congenital anomalies detected by prenatal ultrasound.

METHOD

A retrospective chart review was conducted to collect structural abnormality and genetic testing data on infants who were evaluated postnatally by a medical geneticist. These were used to determine if expanded carrier screening could have determined the etiology prior to delivery. Additionally, recessive and X-linked conditions on clinically available carrier screening panels were evaluated to determine the number of conditions associated with abnormal ultrasound findings.

RESULTS

Our retrospective chart review found 222 patients with genetic etiologies, including eight unique autosomal recessive conditions and six X-linked conditions in the 23% who underwent exome sequencing. Of these 14 unique conditions detected, three were included on a list of 271 conditions for which screening was available in 2019 and five were included on a 500 condition panel available in 2020. A literature review was performed on the list of 271 conditions and 88 were reported to be associated with one or more ultrasound abnormalities.

CONCLUSION

This study demonstrates limited but potential utility for expanded carrier screening to determine the underlying etiology of congenital anomalies.

Performance of a universal prenatal screening program incorporating cell-free fetal DNA analysis in Ontario, Canada

BACKGROUND:

The emergence of cell-free fetal DNA (cfDNA) testing technology has disrupted the landscape of prenatal screening for trisomies 21 (T21) and 18 (T18). Publicly funded systems around the world are grappling with how to best integrate this more accurate but costly technology, as there is limited evidence about its incremental value in real-world conditions. The objectives of this study were to describe the population-based performance of Ontario’s prenatal screening program, which incorporates publicly funded cfDNA screening for specific indications, and the effect of cfDNA testing on the screening and diagnostic choices made by pregnant people.

METHODS:

We conducted a retrospective, descriptive cohort study using routinely collected data from Better Outcomes & Registry Network (BORN) Ontario, which captures linked population data for prenatal and neonatal health encounters across Ontario. We included all singleton pregnancies with an estimated due date between Sept. 1, 2016, and Mar. 31, 2019, that underwent publicly funded prenatal screening in Ontario, and a comparison cohort from Apr. 1, 2012, and Mar. 31, 2013. We assessed performance of the screening program for the detection of T21 or T18 by calculating sensitivity, specificity, positive predictive value and negative predictive value against diagnostic cytogenetic results or birth outcomes. We assessed the impact of the program by calculating the proportion of T21 screen-positive pregnancies undergoing subsequent cfDNA screening and invasive prenatal diagnostic testing.

RESULTS:

The study cohort included 373 682 pregnancies. The prenatal screening program had an uptake of 69.9%, a screen-positive rate and sensitivity of 1.6% and 89.9% for T21, and 0.2% and 80.5% for T18, respectively. The test failure rate for cfDNA screening was 2.2%. Invasive prenatal diagnostic testing decreased from 4.4% in 2012–2013 to 2.4% over the study period; 65.2% of pregnant people who received a screen-positive result from cfDNA testing went on to have invasive prenatal diagnostic testing.

INTERPRETATION:

This publicly funded screening program, incorporating cfDNA analysis for common aneuploidies, showed robust performance, a substantial reduction in invasive prenatal diagnostic testing and that pregnant people exercise autonomy in their choices about prenatal screening and diagnosis.

Introducing cell-free DNA noninvasive testing in a Down syndrome public health screening program: a budget impact analysis

BACKGROUND

Non-invasive prenatal testing (NIPT) using cell-free fetal DNA in maternal plasma is a high accurate test for prenatal screening for Down syndrome. Although it has been reported to be cost effective as a contingent test, evidence about its budget impact is lacking.

OBJECTIVE

To evaluate, using computer simulations, the budget impact of implementing NIPT as a contingent test in the Quebec Program of screening for Trisomy 21.

METHODS

A semi-Markov analytic model built to simulate the budget impact of implementing NIPT into the current Quebec Trisomy 21 public Prenatal Screening, Serum Integrated prenatal screening (SIPS). Comparisons were made for a virtual population similar to that of expected Quebec pregnant women in 2015 in terms of size and age. Data input parameters were retrieved from a thorough literature search and in government databases, especially data from Quebec Program of screening for Trisomy 21. The 2015-2016 fiscal year budget impact was estimated from the Quebec healthcare system perspective and was expressed as the difference in the overall costs between the two alternatives (SIPS minus SPS + NIPT).

RESULTS

Our study found that, at a baseline cost for NIPT of CAD$ 795, NIPT as a second-tier test offered to high-risk women identified by current screening program (SIPS + NIPT) may be affordable for Quebec health care system. Compared to the current screening program, it would be implemented at a neutral cost, considering a modest annual savings of $ 80,432 (95% CI $ 79, $ 874-$ 81,462). Results were sensitive to the NIPT costs and the uptake-rate of invasive diagnostic tests.

CONCLUSION

Introducing NIPT as a contingent test in the Quebec Trisomy 21 screening program is an affordable strategy compared to the current practice. Further research is needed to confirm if our results can be reproduced in other healthcare jurisdictions.

A Retrospective Analysis Of Different Contingent Screening Models For Fetal Down Syndrome In Southwestern China

To discuss combinations of traditional screening and noninvasive prenatal screening (NIPS) and to compare which traditional screening is the most suitable first-line screening approach to NIPS, pregnant women were recruited in this retrospective observational study. Pregnant women underwent one of four traditional screening tests. The 9 contingent models were combined by high risk cut-offs of 1:50, 1:100, 1:270 and intermediate risk cut-offs of 1:1000, 1:1500, 1:2000. We analyzed cost and performance of various screening models with contingent screening of different risk cut-offs. Compared with other screening tests, combined first-trimester screening (CFTS) had the lowest proportion of high risk (≥1:270) with the highest detection rate (DR) (78.79%) and the lowest proportion of intermediate risk (1:271~1:1000). When intermediate risk was 1:51 ~1:1500, CFTS as first-line screening had the lowest cost with DR of 93.94%. Other screening tests as the first-line screening with intermediate risk of 1:51~1:1000 had the lowest cost, there DR were 90.91%, 84.62%, 91.67%, respectively. Our study demonstrated if only one traditional screening was allowed to screen pregnant women, CFTS was recommended as the first choice. According to local health and economic conditions, adopting appropriate traditional screening with suitable cut-offs as first-line screening will contributed to a cost-effective screening model.

Noninvasive Prenatal Testing for Trisomies 21, 18, and 13, Sex Chromosome Aneuploidies, and Microdeletions in Average-Risk Pregnancies: A Cost-Effectiveness Analysis

OBJECTIVE

The cost effectiveness of noninvasive prenatal testing (NIPT) has been established for high-risk pregnancies but remains unclear for pregnancies at other risk levels. The aim was to assess the cost effectiveness of NIPT in average-risk pregnancies from the perspective of a provincial public payer in Canada.

METHODS

A model was developed to compare traditional prenatal screening (TPS), NIPT as a second-tier test (performed only after a positive TPS result), and NIPT as a first-tier test (performed instead of TPS) for trisomies 21, 18, and 13; sex chromosome aneuploidies; and microdeletions in a hypothetical annual population cohort of average-risk pregnancies (142 000 to 148,000) in Ontario, Canada. A probabilistic analysis was conducted with 5000 repetitions.

RESULTS

Compared with TPS, NIPT as a second-tier test detected more affected fetuses with trisomies 21, 18, and 13 (188 vs. 158), substantially reduced the number of diagnostic tests (i.e., chorionic villus sampling and amniocentesis) performed (660 vs. 3107), and reduced the cost of prenatal screening ($26.7 million vs. $27.6 million) annually. Compared with second-tier NIPT, first-tier NIPT detected an additional 80 cases of trisomies 21, 18, and 13 at an additional cost of $33 million. The incremental cost per additional affected fetus detected was $412 411. Extending first-tier NIPT to include testing for sex chromosome aneuploidies and 22q11.2 deletion would increase the total screening cost.

CONCLUSIONS

NIPT as a second-tier test is cost-saving compared with TPS alone. Compared with second-tier NIPT, first-tier NIPT detects more cases of chromosomal anomalies but at a substantially higher cost.

Cost-effectiveness of prenatal screening and diagnostic strategies for Down syndrome: A microsimulation modeling analysis

Objectives

Down syndrome (DS) is the most frequently occurring fetal chromosomal abnormality and different prenatal screening strategies are used for determining risk of DS worldwide. New non-invasive prenatal testing (NIPT), which uses cell-free fetal DNA in maternal blood can provide benefits due to its higher sensitivity and specificity in comparison to conventional screening tests. This study aimed to assess the cost-effectiveness of using population-level NIPT in fetal aneuploidy screening for DS.

Methods

We developed a microsimulation decision-analytic model to perform a probabilistic cost-effectiveness analysis (CEA) of prenatal screening and diagnostic strategies for DS. The model followed individual simulated pregnant women through the pregnancy pathway. The comparators were serum-only screening, contingent NIPT (i.e., NIPT as a second-tier screening test) and universal NIPT (i.e., NIPT as a first-tier screening test). To address uncertainty around the model parameters, the expected values of costs and quality-adjusted life-years (QALYs) in the base case and all scenario analyses were obtained through probabilistic analysis from a Monte Carlo simulation.

Results

Base case and scenario analyses were conducted by repeating the micro-simulation 1,000 times for a sample of 45,605 pregnant women per the population of British Columbia, Canada (N = 4.8 million). Preliminary results of the sequential CEAs showed that contingent NIPT was a dominant strategy compared to serum-only screening. Compared with contingent NIPT, universal NIPT at the current test price was not cost-effective with an incremental cost-effectiveness ratio over $100,000/QALY. Contingent NIPT also had the lowest cost per DS case detected among these three strategies.

Conclusion

Including NIPT in existing prenatal screening for DS is shown to be beneficial over conventional testing. However, at current prices, implementation of NIPT as a second-tier screening test is more cost-effective than deploying it as a universal test.

A 2-year review of publicly funded cell-free DNA screening in Ontario: utilization and adherence to funding criteria

OBJECTIVE

Ontario offers a publicly funded modified contingent model of prenatal screening for aneuploidy in which cell-free DNA (cfDNA) screening is covered for pregnancies at higher risk of fetal aneuploidy. The objective of this study was to review utilization of provincially funded cfDNA screening and adherence to the criteria laid out in Ontario prenatal screening guidelines.

METHODS

This was a descriptive cohort study using data collected by Ontario's prescribed maternal and child registry. The study population included all pregnant individuals who received cfDNA screening from January 2016 to December 2017.

RESULTS

The most common criteria for provincially funded cfDNA screening were advanced maternal age ≥40 years (37.7%), positive multiple marker screen (34.1%), modifying risk factors such as ultrasound soft markers (7.1%), and previous aneuploidy (5.5%). The audit demonstrated that 2.9% of funded cfDNA screens tests did not meet funding criteria, and that 11.4% of self-paid cfDNA screens could have been publicly funded.

CONCLUSION

Reviewing and auditing the application of criteria for funded cfDNA screening using prescribed registry data allows an opportunity to identify areas where targeted education may improve adherence to standardized screening protocols, and provides a basis for reassessment of the funding model.

The role of information provision in economic evaluations of non-invasive prenatal testing: a systematic review

BACKGROUND

Technological progress has led to changes in the antenatal screening programmes, most significantly the introduction of non-invasive prenatal testing (NIPT). The availability of a new type of testing changes the type of information that the parent(s) require before, during and after screening to mitigate anxiety about the testing process and results.

OBJECTIVES

To identify the extent to which economic evaluations of NIPT have accounted for the need to provide information alongside testing and the associated costs and health outcomes of information provision.

METHODS

A systematic review of economic evaluations of NIPTs (up to February 2018) was conducted. Medline, Embase, CINAHL and PsychINFO were searched using an electronic search strategy combining a published economic search filter (from NHS economic evaluations database) with terms related to NIPT and screening-related technologies. Data were extracted using the Consolidated Health Economic Evaluation Reporting Standards framework and the results were summarised as part of a narrative synthesis.

RESULTS

A total of 12 economic evaluations were identified. The majority of evaluations (n = 10; 83.3%) involved cost effectiveness analysis. Only four studies (33.3%) included the cost of providing information about NIPT in their economic evaluation. Two studies considered the impact of test results on parents' quality of life by allowing utility decrements for different outcomes. Some studies suggested that the challenges of valuing information prohibited their inclusion in an economic evaluation.

CONCLUSION

Economic evaluations of NIPTs need to account for the costs and outcomes associated with information provision, otherwise estimates of cost effectiveness may prove inaccurate.

Clinical validation of a novel automated cell-free DNA screening assay for trisomies 21, 13, and 18 in maternal plasma

Objective

To evaluate clinical performance of a new automated cell‐free (cf)DNA assay in maternal plasma screening for trisomies 21, 18, and 13, and to determine fetal sex.

Method

Maternal plasma samples from 1200 singleton pregnancies were analyzed with a new non–sequencing cfDNA method, which is based on imaging and counting specific chromosome targets. Reference outcomes were determined by either cytogenetic testing, of amniotic fluid or chorionic villi, or clinical examination of neonates.

Results

The samples examined included 158 fetal aneuploidies. Sensitivity was 100% (112/112) for trisomy 21, 89% (32/36) for trisomy 18, and 100% (10/10) for trisomy 13. The respective specificities were 100%, 99.5%, and 99.9%. There were five first pass failures (0.4%), all in unaffected pregnancies. Sex classification was performed on 979 of the samples and 99.6% (975/979) provided a concordant result.

Conclusion

The new automated cfDNA assay has high sensitivity and specificity for trisomies 21, 18, and 13 and accurate classification of fetal sex, while maintaining a low failure rate. The study demonstrated that cfDNA testing can be simplified and automated to reduce cost and thereby enabling wider population‐based screening.

What is already known about this topic?

Maternal plasma cell‐free (cf)DNA analysis with next-generation sequencing has a high sensitivity and specificity for fetal trisomy 21 and other common autosomal trisomies.

A new amplification-free, nonsequencing, and targeted cfDNA assay has been developed.

Proof‐of‐principle analysis found the new assay has promising results in screening for trisomy 21.

What does this study add?

The new assay has high sensitivity and specificity for trisomies 21, 18, and 13 in singleton pregnancies.

It can accurately determine fetal sex.

It is suitable for use in biochemical screening laboratories since it is highly automated and does not require specialized personnel.

No. 348-Joint SOGC-CCMG Guideline: Update on Prenatal Screening for Fetal Aneuploidy, Fetal Anomalies, and Adverse Pregnancy Outcomes

OBJECTIVE

To review the available prenatal screening options in light of the recent technical advances and to provide an update of previous guidelines in the field of prenatal screening.

INTENDED USERS

Health care providers involved in prenatal screening, including general practitioners, obstetricians, midwives, maternal fetal medicine specialists, geneticists, and radiologists.

TARGET POPULATION

All pregnant women receiving counselling and providing informed consent for prenatal screening.

EVIDENCE

Published literature was retrieved through searches of Medline, PubMed, and the Cochrane Library in and prior to March 2016 using an appropriate controlled vocabulary (prenatal diagnosis, amniocentesis, chorionic villi sampling, non-invasive prenatal screening) and key words (prenatal screening, prenatal genetic counselling). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English and published from January 1985 to May 2016. Searches were updated on a regular basis and incorporated in the guideline. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical speciality societies.

GUIDELINE UPDATE

Evidence will be reviewed 5 years after publication to determine whether all or part of the guideline should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations.

Allocating healthcare resources to genomic testing in Canada: latest evidence and current challenges

Precision medicine (PM) informed by next-generation sequencing (NGS) poses challenges for health technology assessment (HTA). To date, there has been limited reimbursement of genomic testing with NGS in Canada, particularly for whole-genome and whole-exome sequencing (WGS/WES). Through a structured literature review, we examine Canadian economic evidence and evidentiary challenges for the adoption of genomic testing. We searched Medline (PubMed) for published Canadian studies generating economic evidence for PM informed by NGS. Our search focused on studies examining the costs and/or value of NGS. We reviewed included studies and summarized results according to evaluation type, clinical context, NGS technology, and test strategy. We then grouped HTA challenges encountered by authors when evaluating NGS. Our review included twenty-five studies. To determine the economic impacts of NGS-informed PM in Canada, studies applied cost-effectiveness analysis (52%, n = 13), stated preference analysis (20%, n = 5), cost-consequence analysis (16%, n = 4), and healthcare resource utilization or costing analysis (12%, n = 3). NGS panels were the most common technology evaluated (n = 13), followed by WGS and/or WES (n = 8). The included studies highlighted multiple challenges when generating economic evidence, many of which remain unaddressed. Challenges were broadly related to (1) accounting for all NGS outcomes; (2) addressing uncertainty; and (3) improving consistency of economic approaches. Canadian studies are beginning to produce estimates of the economic impacts of NGS-informed PM, yet challenges for HTA remain. While solutions and real-world evidence are generated, lifecycle health technology management methods can be designed to better support resource allocation decisions for genomic testing in Canada.

Trends in the use of prenatal testing services for fetal aneuploidy in Ontario: a descriptive study

BACKGROUND

In 2014, Ontario augmented its publicly funded multiple-marker screening program for prenatal aneuploidy by incorporating cell-free fetal DNA (cffDNA) analysis for high-risk pregnancies. We assessed trends in the use of multiple-marker screening, cffDNA screening and prenatal diagnostic testing before and after implementation of public funding.

METHODS

We conducted a descriptive study based on data from the Better Outcomes Registry & Network (BORN) Ontario. The study population included all pregnant women in Ontario with a singleton pregnancy and an expected date of delivery between July 1, 2012, and Mar. 31, 2016, with pregnancy data captured in BORN. Pregnancy losses and terminations before 20 weeks' gestation not captured in BORN were excluded. We generated descriptive statistics to show trends and regional variations in use.

RESULTS

The study sample included 534 210 singleton pregnancies. After cffDNA screening was funded for specific indications, uptake of multiple-marker screening increased slightly, from 66.5% to 68.1% (p < 0.001). Uptake of cffDNA screening among women with a positive multiple-marker screening result increased substantially, from 3.2% to 48.8% (p < 0.001). In contrast, the rate of prenatal diagnostic testing in this group decreased from 54.8% to 30.8% (p < 0.001). Although women aged 40 years or older are eligible for primary cffDNA screening, only a small decrease in the use of multiple-marker screening was observed in this group. The greatest use of cffDNA screening and greatest decline in prenatal diagnostic testing were seen in women with a level of risk for trisomy 21 of 1:101-1:200 based on multiple-marker screening.

INTERPRETATION

After public funding of cffDNA screening was implemented in Ontario, there was a significant increase in cffDNA screening and a significant decrease in prenatal diagnostic testing among women with a positive multiple-marker screening result. These changing patterns show the significant impact of public policy and funding decisions on women's choices regarding prenatal testing.

Cost-effectiveness of cell-free DNA in maternal blood testing for prenatal detection of trisomy 21, 18 and 13: a systematic review

The aim of this paper was to conduct a systematic review of the cost-effectiveness of the analysis of cell-free DNA in maternal blood, often called the non-invasive prenatal test (NIPT), in the prenatal screening of trisomy in chromosomes 21, 18 and 13. MEDLINE, MEDLINE in process, EMBASE, and Cochrane Library were searched in April 2017. We selected: (1) economic evaluations that estimated the costs and detected cases of trisomy 21, 18 or 13; (2) comparisons of prenatal screening with NIPT (universal or contingent strategies) and the usual screening without NIPT, (3) in pregnant women with any risk of foetal anomalies. Studies were reviewed by two researchers. Data were extracted, the methodological quality was assessed and a narrative synthesis was prepared. In total, 12 studies were included, four of them performed in Europe. Three studies evaluated NIPT as a contingent test, three studies evaluated a universal NIPT, and six studies evaluated both. The results are heterogeneous, especially for the contingent NIPT where the results range from NIPT being dominant to a dominated strategy. Universal NIPT was found to be more effective but also costlier than the usual screening, with very high incremental cost-effectiveness ratios. One advantage of screening with NIPT is lower invasive procedure-related foetal losses than with usual screening. In conclusion, the cost-effectiveness of contingent NIPT is uncertain according to several studies, while the universal NIPT is not cost-effective currently.

Cell-free DNA noninvasive prenatal screening for aneuploidy versus conventional screening: A systematic review of economic evaluations

Although noninvasive prenatal testing (NIPT) for aneuploidies using cell-free fetal DNA in maternal blood has been reported to have a high accuracy, only little evidence about its cost-effectiveness is available. We systematically reviewed and assessed quality of economic evaluation studies published between January 1, 2009 and January 1, 2016 where NIPT was compared to the current screening practices consisting of biochemical markers with or without nuchal translucency (NT) and/or maternal age. We included 16 studies and we found that, at current level of NIPT prices, contingent NIPT provide the best value for money, especially for publicly funded screening programs. NIPT as first-line test was found not cost-effective in the majority of studies. The NIPT unit cost, the risk cut-offs for current screening practice, the screening uptake rates (first- and second-line screening) as well as the costs and uptake rates of invasive diagnostic screening were the most common uncertain variables. The overall quality of included studies was fair. Considering a possible drop in prices and an ongoing NIPT expansion to include other chromosomes abnormalities other than T21, T18, T13 and sex chromosomes aneuploidies, future research are needed to examine the potential cost-effectiveness of implementing NIPT as first-line test.

Cell-Free DNA-Based Non-invasive Prenatal Screening for Common Aneuploidies in a Canadian Province: A Cost-Effectiveness Analysis

OBJECTIVE

Yearly, 450 000 pregnant Canadians are eligible for voluntary prenatal screening for trisomy 21. Different screening strategies select approximately 4% of women for invasive fetal chromosome testing. Non-invasive prenatal testing (NIPT) using maternal blood cell-free DNA could reduce those invasive procedures but is expensive. This study evaluated the cost-effectiveness of NIPT strategies compared with conventional strategies.

METHODS

This study used a decision analytic model to estimate the cost-effectiveness of 13 prenatal screening strategies for fetal aneuploidies: six frequently used strategies, universal NIPT, and six strategies incorporating NIPT as a second-tier test. The study considered a virtual cohort of pregnant women of similar size and age as women in Quebec. Model data were obtained from published sources and government databases. The study predicted the number of chromosomal anomalies detected (trisomies 21, 13, and 18), invasive procedures and euploid fetal losses, direct costs, and incremental cost-effectiveness ratios.

RESULTS

Of the 13 strategies compared, eight identified fewer cases at a higher cost than at least one of the remaining five strategies. Integrated serum screening with conditional NIPT had the lowest cost, and the cost per case detected was $63 139, with a 90% reduction of invasive procedures. The number of cases identified was improved with four other screening strategies, but with increasing of incremental costs per case (from $61 623 to $1 553 615). Results remained robust, except when NIPT costs and risk cut-offs varied.

CONCLUSION

NIPT as a second-tier test for high-risk women is likely to be cost-effective as compared with screening algorithms not involving NIPT.

Expanded conventional first trimester screening

Objective

The study aims to determine the performance of a five (5) serum marker plus ultrasound screening protocol for T21, T18 and T13.

Method

Specimens from 331 unaffected, 34 T21, 19 T18 and 8 T13 cases were analyzed for free Beta human chorionic gonadotropin, pregnancy‐associated plasma protein A, alpha‐fetoprotein, placental growth factor and dimeric inhibin A. Gaussian distributions of multiples of the median values were used to estimate modeled false positive and detection rates (DR).

Results

For T21, at a 1/300 risk cut‐off, DR of screening with all five serum markers along with nuchal translucency and nasal bone was 98% at a 1.2% false positive rate (FPR). Using a 1/1000 cut‐off, the DR was 99% with a 2.6% FPR. For T18/13 with free Beta human chorionic gonadotropin, pregnancy‐associated plasma protein A, placental growth factor and nuchal translucency at a 1/150 cut‐off, DR was 95% at a 0.5% FPR while at a 1/500 risk cut‐off, DR was 97% at a 1.2% FPR.

Conclusion

An expanded conventional screening test can achieve very high DRs with low FPRs. Such screening fits well with proposed contingency protocols utilizing cell‐free DNA as a secondary or reflex but also provides the advantages of identification of pregnancies at risk for other adverse outcomes such as early‐onset preeclampsia. © 2017 Eurofins NTD, LLC. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

What's already known about this topic?

Conventional Down syndrome screening with ultrasound markers and free Beta hCG and PAPP‐A has been successfully utilized for nearly 20 years to screen for trisomies 21, 18 and 13.

Cell‐free DNA screening has much higher detection and lower false positive rates but is expensive.

What does this study add?

An expanded conventional screen with nuchal translucency and nasal bone that includes additional serum markers AFP, placental growth factor and dimeric inhibin A can detect 98% of trisomy 21 and 95% of trisomy 18/13 cases at a false positive rate of 1.2% and 0.5%, respectively.

Offering cell‐free DNA testing to those patients found at increased risk with the expanded screen maintains the detection efficiency but brings the invasive testing rate to an exceedingly low level.

Uptake, outcomes, and costs of implementing non-invasive prenatal testing for Down's syndrome into NHS maternity care: prospective cohort study in eight diverse maternity units

OBJECTIVE

 To investigate the benefits and costs of implementing non-invasive prenatal testing (NIPT) for Down's syndrome into the NHS maternity care pathway.

DESIGN

 Prospective cohort study.

SETTING

 Eight maternity units across the United Kingdom between 1 November 2013 and 28 February 2015.

PARTICIPANTS

 All pregnant women with a current Down's syndrome risk on screening of at least 1/1000.

MAIN OUTCOME MEASURES

 Outcomes were uptake of NIPT, number of cases of Down's syndrome detected, invasive tests performed, and miscarriages avoided. Pregnancy outcomes and costs associated with implementation of NIPT, compared with current screening, were determined using study data on NIPT uptake and invasive testing in combination with national datasets.

RESULTS

 NIPT was prospectively offered to 3175 pregnant women. In 934 women with a Down's syndrome risk greater than 1/150, 695 (74.4%) chose NIPT, 166 (17.8%) chose invasive testing, and 73 (7.8%) declined further testing. Of 2241 women with risks between 1/151 and 1/1000, 1799 (80.3%) chose NIPT. Of 71 pregnancies with a confirmed diagnosis of Down's syndrome, 13/42 (31%) with the diagnosis after NIPT and 2/29 (7%) after direct invasive testing continued, resulting in 12 live births. In an annual screening population of 698 500, offering NIPT as a contingent test to women with a Down's syndrome screening risk of at least 1/150 would increase detection by 195 (95% uncertainty interval -34 to 480) cases with 3368 (2279 to 4027) fewer invasive tests and 17 (7 to 30) fewer procedure related miscarriages, for a non-significant difference in total costs (£-46 000, £-1 802 000 to £2 661 000). The marginal cost of NIPT testing strategies versus current screening is very sensitive to NIPT costs; at a screening threshold of 1/150, NIPT would be cheaper than current screening if it cost less than £256. Lowering the risk threshold increases the number of Down's syndrome cases detected and overall costs, while maintaining the reduction in invasive tests and procedure related miscarriages.

CONCLUSIONS

 Implementation of NIPT as a contingent test within a public sector Down's syndrome screening programme can improve quality of care, choices for women, and overall performance within the current budget. As some women use NIPT for information only, the Down's syndrome live birth rate may not change significantly. Future research should consider NIPT uptake and informed decision making outside of a research setting.

Non-invasive prenatal testing for fetal chromosome abnormalities: review of clinical and ethical issues

Genomics-based non-invasive prenatal screening using cell-free DNA (cfDNA screening) was proposed to reduce the number of invasive procedures in current prenatal diagnosis for fetal aneuploidies. We review here the clinical and ethical issues of cfDNA screening. To date, it is not clear how cfDNA screening is going to impact the performances of clinical prenatal diagnosis and how it could be incorporated in real life. The direct marketing to users may have facilitated the early introduction of cfDNA screening into clinical practice despite limited evidence-based independent research data supporting this rapid shift. There is a need to address the most important ethical, legal, and social issues before its implementation in a mass setting. Its introduction might worsen current tendencies to neglect the reproductive autonomy of pregnant women.

Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non-laboratory aspects such as information and counseling), education of professionals, systematic evaluation of all aspects of prenatal screening, development of better evaluation tools in the light of the aim of the practice, accountability to all stakeholders including children born from screened pregnancies and persons living with the conditions targeted in prenatal screening and promotion of equity of access.

An Economic Analysis of Cell-Free DNA Non-Invasive Prenatal Testing in the US General Pregnancy Population

OBJECTIVE

Analyze the economic value of replacing conventional fetal aneuploidy screening approaches with non-invasive prenatal testing (NIPT) in the general pregnancy population.

METHODS

Using decision-analysis modeling, we compared conventional screening to NIPT with cell-free DNA (cfDNA) analysis in the annual US pregnancy population. Sensitivity and specificity for fetal aneuploidies, trisomy 21, trisomy 18, trisomy 13, and monosomy X, were estimated using published data and modeling of both first- and second trimester screening. Costs were assigned for each prenatal test component and for an affected birth. The overall cost to the healthcare system considered screening costs, the number of aneuploid cases detected, invasive procedures performed, procedure-related euploid losses, and affected pregnancies averted. Sensitivity analyses evaluated the effect of variation in parameters. Costs were reported in 2014 US Dollars.

RESULTS

Replacing conventional screening with NIPT would reduce healthcare costs if it can be provided for $744 or less in the general pregnancy population. The most influential variables were timing of screening entry, screening costs, and pregnancy termination rates. Of the 13,176 affected pregnancies undergoing screening, NIPT detected 96.5% (12,717/13,176) of cases, compared with 85.9% (11,314/13,176) by conventional approaches. NIPT reduced invasive procedures by 60.0%, with NIPT and conventional methods resulting in 24,596 and 61,430 invasive procedures, respectively. The number of procedure-related euploid fetal losses was reduced by 73.5% (194/264) in the general screening population.

CONCLUSION

Based on our analysis, universal application of NIPT would increase fetal aneuploidy detection rates and can be economically justified. Offering this testing to all pregnant women is associated with substantial prenatal healthcare benefits.

Evaluating first trimester maternal serum screening combinations for Down syndrome suitable for use with reflexive secondary screening via sequencing of cell free DNA: high detection with low rates of invasive procedures

OBJECTIVES

Examine primary Down syndrome screening using combinations of first trimester serum markers, with and without sequencing of cell free DNA as a secondary reflexive test.

METHODS

Samples from 40 Down syndrome cases were matched with five control samples and tested for PAPP-A, free β, AFP, inhibin-A and PlGF. Results were converted to weight-adjusted multiples of the median (MoM) and population parameters computed. Monte Carlo simulation modeled Down syndrome detection and false positive rates for various marker combinations. After reflexive DNA testing, the revised detection and false positive rates were also computed.

RESULTS

At a primary false positive rate of 20%, the baseline combination (maternal age, PAPP-A and free β) detected 86.9%. Adding AFP or PlGF increased detection to 89.8% and 89.5%, respectively. Adding AFP and PlGF, AFP and inhibin-A, or all three markers, detected 93.7%, 94.1% and 95.5%, respectively. Modeling reflexive cf DNA testing results in little loss in detection (1%), but false positive rates fall to 0.2%.

CONCLUSION

First trimester reflexive testing does not require nuchal translucency measurements, and has high detection and very low rates of invasive procedures. However, timing of DNA sample collection and the costs of sample collection and DNA testing need to be considered before implementation.

Overview of the impact of noninvasive prenatal testing on diagnostic procedures

Noninvasive prenatal testing (NIPT) has had a profound influence in the field of prenatal diagnosis since the 1997 discovery of cell-free fetal DNA in maternal blood. Research has progressed rapidly, with clinical data supporting laboratory studies showing that NIPT is highly sensitive and specific for fetal aneuploidy, resulting in marked uptake in the high-risk patient population. The superior accuracy of NIPT compared with conventional screening methods has led to significant decreases in the number of invasive diagnostic procedures, in addition to a concomitant decrease in the number of procedure-related fetal losses. Yet, NIPT has been described as a 'disruptive innovation' due to the considerable changes the technology has commanded on current prenatal screening and diagnostic practices. This review summarizes both institutional and global experience with NIPT uptake, its effect on reducing diagnostic invasive procedures, and the unique challenges that reduced procedural volume may have on physician and trainee proficiency, cytogenetic laboratories, and neonatal outcome.

Incorporation of dried blood alpha fetoprotein into traditional first trimester Down syndrome screening service

Abstract

What’s already known about this topic?

What does this study add?

Performance of antenatal reflex DNA screening for Down's syndrome

OBJECTIVE

Maternal plasma DNA analysis has a high but imperfect antenatal Down's syndrome screening performance. We aimed to determine the effect of combining DNA testing with current tests.

METHODS

In our modelled screening protocol, women provide two samples, one serum sample for a Combined test, and a plasma sample for a possible DNA test. Women with a Combined test risk above a specified level have a DNA test using the plasma sample without the need to recall them for another sample and counselling (ie. in a reflex manner). Women with a failed DNA test after a second attempt using a fresh plasma sample have an Integrated test. Screening performance was estimated according to the proportion of women reflexed to DNA testing and compared with universal DNA testing.

RESULTS

Reflexing 10% of women to a DNA test yields a 91% detection rate (DR) for a 0.025% false-positive rate (FPR) and no failed tests, compared with a 98% DR, 0.2% FPR and a 2.5% test failure rate with universal DNA testing (94% for 0.046% if 20% reflexed). DNA test failure rate has little influence on screening performance

CONCLUSION

Reflex DNA testing substantially reduces the FPR with a relatively small loss in detection compared with universal DNA testing, and reduces patient anxiety by avoiding the recall of women for DNA testing.

Dilemmas in Prenatal Chromosomal Diagnosis Revealed Through a Single Center's 30 Years' Experience and 90,000 Cases

INTRODUCTION

The aim of this article is to provide a perspective of prenatal chromosomal diagnosis (PCD) derived from a single center's evolving experience from ∼90,000 consecutive prenatal cases and to highlight important issues and current dilemmas.

MATERIALS AND METHODS

Prenatal cases in this study (1985-2013) were referred for various indications, and PCD was performed by standard karyotype in 84,255 cases, multiplex ligation-dependent probe amplification (MLPA) panel in 3,010 cases and standalone array comparative genomic hybridization (aCGH) in 3,122 cases.

RESULTS

Classic karyotype revealed 1.7 and 7.9% of pathological cases in amniotic fluid and CVS samples, respectively, with common aneuploidies accounting for 59.6 and 64.3% of the total abnormal. Molecular approaches increased the diagnostic yield by 0.6% for MLPA and 1.6% for aCGH, uncovering pathogenic chromosomal abnormalities undetectable by karyotype analysis.

CONCLUSIONS

Current molecular diagnostic capabilities and the recent introduction of noninvasive prenatal testing (NIPT) point to one current major dilemma in PCD, with serious implications in genetic counseling, relating on the one hand to reaping the benefits from the high detection rate afforded through aCGH but accepting an invasive risk, and on the other hand, offering a lower detection rate practically only for Down syndrome, with minimal invasive risk.

Cell-free fetal DNA screening in the USA: a cost analysis of screening strategies

OBJECTIVES

To determine whether implementation of primary cell-free fetal DNA (cffDNA) screening would be cost-effective in the USA and to evaluate potential lower-cost alternatives.

METHODS

Three strategies to screen for trisomy 21 were evaluated using decision tree analysis: 1) a primary strategy in which cffDNA screening was offered to all patients, 2) a contingent strategy in which cffDNA screening was offered only to patients who were high risk on traditional first-trimester screening and 3) a hybrid strategy in which cffDNA screening was offered to all patients ≥ 35 years of age and only to patients < 35 years who were high risk after first-trimester screening. Four traditional screening protocols were evaluated, each assessing nuchal translucency (NT) and pregnancy-associated plasma protein-A (PAPP-A) along with either free or total beta-human chorionic gonadotropin (β-hCG), with or without nasal bone (NB) assessment.

RESULTS

Utilizing a primary cffDNA screening strategy, the cost per patient was 1017 US$. With a traditional screening protocol using free β-hCG, PAPP-A and NT assessment as part of a hybrid screening strategy, a contingent strategy with a 1/300 cut-off and a contingent strategy with a 1/1000 cut-off, the cost per patient was 474, 430 and 409 US$, respectively. Findings were similar using the other traditional screening protocols. Marginal cost per viable case detected for the primary screening strategy as compared to the other strategies was 3-16 times greater than the cost of care for a missed case.

CONCLUSIONS

Primary cffDNA screening is not currently a cost-effective strategy. The contingent strategy was the lowest-cost alternative, especially with a risk cut-off of 1/1000. The hybrid strategy, although less costly than primary cffDNA screening, was more costly than the contingent strategy.

Introducing the non-invasive prenatal test for trisomy 21 in Belgium: a cost-consequences analysis

BACKGROUND

The first- and second-trimester screening for trisomy 21 (T21) are reimbursed for all pregnant women in Belgium. Using a cut-off risk of 1:300 for T21, about 5% of all pregnant women are referred for definitive prenatal diagnosis using an invasive test, at a sensitivity of (only) 72.5%. The sensitivity and specificity of the non-invasive prenatal test (NIPT) are over 99% but come at a cost of €460 (£373) per test. The objective is to estimate the consequences of introducing NIPT for the detection of T21.

METHODS

A cost-consequences analysis was performed presenting the impact on benefits, harms and costs. Context-specific real-world information was available to set up a model reflecting the current screening situation in Belgium. This model was used to construct the second and first line NIPT screening scenarios applying information from the literature on NIPT's test accuracy.

RESULTS

Introducing NIPT in the first or second line reduces harm by decreasing the number of procedure-related miscarriages after invasive testing. In contrast with NIPT in the second line, offering NIPT in the first line additionally will miss fewer cases of T21 due to less false-negative test results. The introduction of NIPT in the second line results in cost savings, which is not true for NIPT at the current price in the first line. If NIPT is offered to all pregnant women, the price should be lowered to about €150 to keep the screening cost per T21 diagnosis constant.

CONCLUSIONS

In Belgium, the introduction and reimbursement of NIPT as a second line triage test significantly reduces procedure-related miscarriages without increasing the short-term screening costs. Offering and reimbursing NIPT in the first line to all pregnant women is preferred in the long term, as it would, in addition, miss fewer cases of T21. However, taking into account the government's limited resources for universal reimbursement, the price of NIPT should first be lowered substantially before this can be realised.